In the past, an optical coherent tomography imaging apparatus for diagnosis (OCT) (for example, see Japanese Unexamined Patent Publication No. 2005-196080) or an optical frequency domain imaging (OFDI) apparatus utilizing wavelength sweep, which is an improved type of OCT, has been widely utilized for diagnosis before an operation through treatment inside a blood vessel with a high functional catheter such as a balloon catheter, a stent or the like, or for a result confirmation after an operation (hereinafter, in this disclosure, the optical coherent tomography imaging apparatus for diagnosis (OCT) and the optical frequency domain imaging (OFDI) apparatus utilizing wavelength sweep will be generically referred to as “imaging apparatus for diagnosis”).
In the imaging apparatus for diagnosis, an optical probe unit includes an imaging core having an optical lens and an optical mirror (transmitting and receiving unit). When a measurement is being made (for example, a diagnosis), the optical probe unit is inserted inside a blood vessel and, while rotating the imaging core with a scanner and pull-back unit (adapter apparatus), a measurement light is emanated from the transmitting and receiving unit at the distal end into the blood vessel and concurrently, reflected light from the biological tissue is light-received. Thus, a radial scan inside the blood vessel is carried out. Then, interference light is generated by making the afore-mentioned light-received reflected-light and the reference light interfere with each other such that a tomographic image of the blood vessel is visualized based on the afore-mentioned interference light. With respect to the imaging apparatus for diagnosis, there is also known an apparatus using ultra-sound or other imaging technologies other than the system using light mentioned above.
The optical probe unit is provided with a connector to be connected to the scanner and pull-back unit. In the optical probe unit, a signal (light, electrical signal) is received from the scanner and pull-back unit through the connector. Therefore, it is necessary to prevent the connector from becoming dirty as would be caused by a foreign matter such as liquid (for example, blood, saline), dust or the like becoming attached or contacting the connector.
In case of a situation in which the connector has become dirty and has become wet due to foreign matters such as a liquid, i.e., blood, saline or the like, or dust and the like, there is a possibility that the following problems or similar such problems may be caused.    1. Electric Shock to Patient    2. Contamination of Optical Probe Unit    3. Rust and/or Corrosion of Scanner and Pull-back Unit    4. Attenuation of Signal (Optical Loss, etc.)
In order to remedy the above issues, there is known a technology in which the connection end surface of the connector is protected by using a cap or the like which is formed by plastic, a flexible resin or similar material. However, even if protecting the connection end surface by using such a cap, if the operator's hand becomes wet such as caused by saline, blood or the like when the operator disengages the cap, there is a possibility that the connection end surface of the connector will become wet.
More specifically, even if the connection end surface of the connector is protected by a cap, it is possible for the operator to easily touch the connector, so that there is still a risk that the connection end surface will become dirty from a foreign matter such as blood, saline, etc.